When sent into an area with a high risk of exposure to chemical weapon agents (“CWA”), troops are deployed in mission oriented protective posture (“MOPP”) gear, and are required to remain in the gear until either the threat passes or they leave the high risk area. The goal of MOPP apparel is to prevent transport of chemical and biological agents. Currently this is achieved using MOPP apparel that includes pore-less polymeric coatings. However, in addition to being impermeable to harmful species, the coating is a barrier for moisture transport. As a result, evaporative cooling through sweating, along with conductive, convective, and radiative cooling is significantly diminished, or completely prevented. This places a significant thermal load on the soldier, and limits the safe use of MOPP gear to about 1 hour in a moderate climate. This time limit is even further decreased in regions such as the Middle-East that can experience significant solar loads and ambient temperatures above 130° F. Consequently, to enable working in MOPP gear for any extended period of time, additional special garments must be worn, including garments with cooling provided by phase change materials (e.g. ice) or using active fluid pumping. Although effective, the addition of a cooling system increases the size, weight, complexity, and cost of the MOPP gear. Furthermore, additional requirements for operation may not always be available in the field, such as batteries or other power sources to run pumps or refrigeration units to pre-freeze the phase change material. In addition, highly specialized cooled MOPP gear may not be readily available in case of a surprise attack, for example, such as in the case of the recent Sarin attack in Syria. Further, in addition to the problems posed by thermal issues, many materials currently utilized in MOPP gear can absorb varying amounts of some CWA, which has the potential to cause a range of serious problems with their use in the field, including, for example, post-exposure CWA release outside of a high risk zone. The majority of CWA substances are low vapor pressure and surface tension liquids with extreme toxicity that are spread in aerosol form. Consequently, to rapidly form an effective barrier, the barrier materials must seal upon contact with a few micro-droplets of the liquid.